PROBLEM: Our previous study indicated that meconium-stained amniotic fluid
(turbid AF) possessed a potent chemotactic activity for leukocytes, which m
ay be dependent on interleukin-8. It is not known, however, whether meconiu
m itself possesses this chemotactic activity.
METHOD OF STUDY: Meconium samples were collected from mature neonates with
and without turbid AF. A 5% meconium suspension in phosphate buffered salin
e was prepared and measured for its chemotactic activity for leukocytes usi
ng the blind well chamber technique. Concentrations of IL-8, TNF alpha and
IL-1 beta were also measured with ELISA.
RESULTS: The number of leukocytes that migrated to the meconium suspension
(35 +/- 27) was comparable with that of the clear AF (31 +/- 37), but was s
ignificantly lower than that of the turbid AF (184 +/- 62, P < 0.0001). The
meconium suspension contained much lower levels of IL-8, TNF<alpha> and IL
-1 beta than the turbid AF.
CONCLUSIONS: Meconium itself exhibits a lower chemotactic activity for poly
morphonuclear leukocytes than turbid AF in vitro. The leukocyte chemotactic
activity of turbid AF does not originate from meconium itself.